The present disclosure relates generally to communication between electronic devices and in particular to device authentication using lists of known good and/or known bad devices.
Portable electronic devices, such as smart phones, tablet computers, media players, and the like, have become ubiquitous. Various accessories have been created to interoperate with portable electronic devices to extend their functionality and/or enhance the user experience. Examples of accessories include chargers, speaker docks, in-vehicle docks that provide options for controlling the portable device using the vehicle's console, workout equipment, health monitoring accessories (e.g., heart rate, blood pressure or glucose meters), and so on. Accessories can be designed to interoperate with multiple portable electronic devices that may differ in their form factor and capabilities (e.g., processing power; firmware version; battery life, presence or absence of cameras, microphones, or other components) and may connect to various portable devices using wired and/or wireless interfaces.
To provide a reliably pleasant experience for a user operating a portable device in conjunction with an accessory, it can be desirable to limit interoperation to authorized accessories. For example, upon connecting to a portable device, the accessory can be required to provide identifying information and/or perform authentication. These processes, however, take time to complete and can be disruptive to the user experience.